Studies on the role of calcium in the control of thromboxane B2 production.
5-hydroxytryptamine (5-ht) secretion and thromboxane B2 (TxB2) production by platelet-rich plasma in response to the Ionophore A23187 or the sulphydryl group reagent N-ethyl maleimide (NEM) were potentiated in the presence of EDTA. No such potentiation by EDTA was observed using aspirin-treated platelets. The addition of Ca2+ and also Mg2+ to suspensions of washed human platelets reduced the rate and extent of TxB2 formation in response to thrombin, A23187, collagen or NEM. In contrast, Sr2+ resulted in spontaneous TxB2 production and 5-HT secretion.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D004492:Edetic Acid / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism; D013324:Strontium / Q000494:pharmacology; D013929:Thromboxane B2 / Q000096:biosynthesis*; D013931:Thromboxanes / Q000096:biosynthesis*
D013931:Thromboxanes; D012701:Serotonin; D000001:Calcimycin; D013929:Thromboxane B2; D004492:Edetic Acid; D005033:Ethylmaleimide; D002118:Calcium; D013324:Strontium